Bonanza "Landing Gear Safety System"

[Roy Smith]

My club recently bought an S35 Bonanza with the optional "Landing Gear
Safety System" installed. I've got the POH supplement that describes
its operation, but nobody seems to know much about how it works.

The gist is that when the airspeed and MP go below certain limits, it
automatically extends the gear, to help prevent accidental gear-up
landings.

Our Arrow has a similar sort of system which works off a 2nd pitot. I
don't see any such 2nd pitot on this plane, so I don't know where it
gets its information from. I could see it having some interconnection
to the throttle knob so it can estimate the MP (and the POH hints at
this), but it also appears to work off airspeed. I can't imagine it
having a mechanical pickup off the ASI.

Does anybody know how this system is designed? How things are
interconnected to get the functionality?

[Mark Mallory]

Roy Smith wrote:

> Our Arrow has a similar sort of system which works off a 2nd pitot. I
> don't see any such 2nd pitot on this plane, so I don't know where it
> gets its information from. I could see it having some interconnection

Why couldn't it work off the same pitot as the ASI?

[Dave Butler]

Mark Mallory wrote:
>
>
> Roy Smith wrote:
>
> > Our Arrow has a similar sort of system which works off a 2nd pitot. I
> > don't see any such 2nd pitot on this plane, so I don't know where it
> > gets its information from. I could see it having some interconnection
>
> Why couldn't it work off the same pitot as the ASI?
>

Don't know the answer to Roy's question, but if it does work off the same pitot
tube, it has the advantage of being heated, whereas the 2nd pitot on the Arrow
has no heat.

Dave
Remove SHIRT to reply directly.

[Ron Natalie]

"Roy Smith" > wrote in message ...

> Our Arrow has a similar sort of system which works off a 2nd pitot. I
> don't see any such 2nd pitot on this plane, so I don't know where it
> gets its information from. I could see it having some interconnection
> to the throttle knob so it can estimate the MP (and the POH hints at
> this), but it also appears to work off airspeed. I can't imagine it
> having a mechanical pickup off the ASI.

The description I have is as follows:


Basically, there's an extra microswitch on the throttle control to sense the power setting and two pressure switches plumbed into
the pitot line. When the system senses a) a power setting below about 18" MP and, b) an airspeed below 120 mph, the circuit closes
and the gear is automatically extended. The system can also work to prevent gear retraction at full throttle and less than about 90
mph.